A few months ago, I drew this rough image in black brush pen. To give an idea what the image might look like as a final draft, it is a good idea to colour your images with a brush pen. Then you can use these as a colour guide for future reference.
I used Canary Yellow and Denim Blue--colours which complement each other very well.
Drawing the outlines do not take very long; colouring in doesn't take very long either. As an artist, it is very useful to have a supply of brush pens. But if you are not sure which brush pens to buy, you only need primary colours.
Primary colours make your pictures look bold and colourful. Often this makes them much more than a picture; they become framed pictures that work well against a beige wall.